99mTc标记COI配合物的制备及其用作心室显像剂的初步研究

通过改变异腈配体的结构和配合物的中心核,以期获得标记方法简单、放化纯度高以及生物性能优良的新型心室显像剂.以环辛胺为原料,通过甲酰胺化和脱水两步反应制得配体环辛基异腈(COI),并以氯化亚锡为还原剂和二硫代肼基甲酸甲酯为供氮体,通过配体交换反应得到放化纯度大于95%的^99mTcN-COI标记物.以氯化亚锡为还原剂直接标记制得放化纯度大于95%的^99mTc-COI配合物.两种标记物在室温下放置6h以上,其放化纯度无明显变化.在正常昆明小鼠体内进行的生物分布实验研究结果显示,^99mTcN-COI和^99mTc-COI在心脑中有一定摄取,但肝、肺及血等本底摄取相对较高.二者在血液中都有很高的浓集,且滞留也很好,其中^99mTc-COI配合物在静脉注射后60min时的血/心、血/肝和血/肺摄取比分别为6.67,1.54和2.07,有望成为一种新型的制备方法简单的心室显像剂.

Preparation and Biodistribution of a Novel Potential Blood Pool Imaging Agent Technetium-99m Labeled COI Complexes

The objective of this study is to develop a new potential cardiac blood pool imaging agent. An isonitrile ligand cyclooctylisonitrile(COI) is synthesized and a copper salt[Cu(Ⅰ)(COI) ₄BF₄] of this ligand is also prepared, the isonitrile and it′s copper salt are characterized by IR and elemental analysis. The complex ^99mTcN-COI is prepared by ligand exchange reaction while the complex ^99mTc-COI is prepared by a direct labeling method. The results of stability study indicated that both complexes are stable over a period of 6 h at room temperature. The biodistribution of these new complexes in mice indicated that they had significantly different uptake properties in most tissues. But they are all mainly accumulated in blood and maintained in it very good. Especially the T/NT ratios of ^99mTc-COI in mice are excellent as a cardiac blood pool imaging agent. Based on its promising properties, the complex ^99mTc-COI maybe suitable for cardiac blood pool imaging.